Search

Organic materials have attracted considerable attention in nonlinear optical (NLO) applications as they have several advantages over inorganic materials, including high NLO response, and fast response time as well as low-cost and easy fabrication. Lithium-containing C 60 (Li@C 60 ) is promising for NLO over other organic materials because of its strong NLO response proven by theoretical and experimental studies. However, the low purity of Li@C 60 has been a bottleneck for applications in the fields of solar cells, electronics and optics. In 2010, highly purified Li@C 60 was finally obtained, encouraging further studies. In this study, we demonstrate a facile method to fabricate thin films of Li@C 60 and their strong NLO potential for high harmonic generation by showing its comparatively strong emission of degenerate-six-wave mixing, a fifth-order NLO effect., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

As medical doctors, we routinely check patient blood chemistry and CBC data to diagnose disease. However, these data and methods of analysis are very rarely used to find pre-disease conditions or treat undiagnosed malaise. Masatoshi Kaneko Ph.D. found that many pre-disease conditions and types of malaise could be detected using his unique method of blood data analysis, and could also be treated using personalized nutritional therapy as an alternative to using drugs. The authors of this article introduce personalized nutritional therapy based on blood data analysis (Kaneko's method), and present and discuss some clinical cases. In total, 253 pre-disease or undiagnosed patients were treated using this nutritional therapy approach, and most of them recovered from their chronic symptoms and pre-disease conditions. This novel nutritional therapy has the potential to help many presymptomatic and undiagnosed patients suffering from malaise.

The structural investigation of synthesized compounds can be carried out by various spectroscopic techniques. It is an important prospect in order to elucidate the structure of the desired products before being further utilized. The preparation of new p-nitro stilbene Schiff base derivatives as an electrochemical DNA potential spacer was synthesized using (E)-4-(4-nitrostyryl)aniline from Heck reaction with aldehydes in ethanolic solution. The data presented here in this article contains FTIR, UV-Vis and 1 H and 13 C NMR of (E)-4-(4-nitrostyryl)aniline and nitrostyryl aniline derivatives., (© 2020 The Author(s).)

The increasing availability of X-ray free-electron lasers (XFELs) has catalyzed the development of single-object structural determination and of structural dynamics tracking in real-time. Disentangling the molecular-level reactions triggered by the interaction with an XFEL pulse is a fundamental step towards developing such applications. Here we report real-time observations of XFEL-induced electronic decay via short-lived transient electronic states in the diiodomethane molecule, using a femtosecond near-infrared probe laser. We determine the lifetimes of the transient states populated during the XFEL-induced Auger cascades and find that multiply charged iodine ions are issued from short-lived (∼20 fs) transient states, whereas the singly charged ones originate from significantly longer-lived states (∼100 fs). We identify the mechanisms behind these different time scales: contrary to the short-lived transient states which relax by molecular Auger decay, the long-lived ones decay by an interatomic Coulombic decay between two iodine atoms, during the molecular fragmentation.

We previously identified a novel nanomagnetic particle, N,N'-bis(salicylidene)ethylenediamine iron [Fe(Salen)]. Fe(Salen) not only shows antitumor effects but also magnetic properties. We found that Fe(Salen) can be used for magnet-guided drug delivery and visualization of accumulated drug by magnetic resonance imaging (MRI) because of its magnetism. In addition, Fe(Salen) can generate heat by itself when exposed to an alternating current magnetic field (AMF), resulting in a hyperthermia effect. Herein, we partly elucidated the antitumor mechanism of Fe(Salen) and carried out an i.v. repeated dose toxicity study to decide the therapeutic amount. Furthermore, we evaluated the antitumor effect of selective intra-arterial injection or i.v. injection of Fe(Salen) by catheter and the hyperthermia effect of Fe(Salen) when exposed to AMF in vivo. We used a rabbit model grafted with VX2 cells (rabbit squamous cell carcinoma) on the right leg. Intra-arterial injection of Fe(Salen) showed a greater antitumor effect than did i.v. injection. The combination of Fe(Salen) intra-arterial injection and AMF exposure showed a greater antitumor effect than did either Fe(Salen) or methotrexate (MTX) without AMF exposure, suggesting that AMF exposure greatly enhanced the antitumor effect of Fe(Salen) by arterial injection by catheter. This is the first report that the effectiveness of Fe(Salen) was evaluated in the point of administration route; that is, selective intra-arterial injection by catheter. Taken together, these results indicate a new administration route; that is, selective arterial injection of Fe(Salen) by catheter, and the development of a new strategy of simultaneous hyperthermia-chemotherapy in the future., (© 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Phase separation dynamics of a water/2-butoxyethanol (2BE) mixture was studied with newly developed time-resolved structured illumination microscopy (SIM). Interestingly, an employed hydrophobic fluorescent probe for SIM showed spectral shifts up to 500 ns after a laser-induced temperature jump, which suggests 2BE micellar-like aggregates become more hydrophobic at the initial stage of phase separation. This hydrophobic environment in 2BE aggregates, probably due to the ejection of water molecules, continued up to at least 10 μs. Time-resolved SIM and previously reported light scattering data clearly showed that the size of a periodic structure remained constant (ca. 300 nm) from 3 to 10 μs, and then the growth of periodic structures having the self-similarity started. We think that the former and the latter processes correspond to "early stage" (concentration growth) and "late stage" (size growth), respectively, in phase separation dynamics. Here we suggest that, in the early stage, the entity to bear 2BE phase be water-poor 2BE aggregates, and the number density of these aggregates would simply increase in time.

Iron-salen, i.e., μ-oxo-N,N'-bis(salicylidene)ethylenediamine iron (Fe(Salen)) was a recently identified as a new anti-cancer compound with intrinsic magnetic properties. Chelation therapy has been widely used in management of metallic poisoning, because an administration of agents that bind metals can prevent potential lethal effects of particular metal. In this study, we confirmed the therapeutic effect of deferoxamine mesylate (DFO) chelation against Fe(Salen) as part of the chelator antidote efficacy. DFO administration resulted in reduced cytotoxicity and ROS generation by Fe(Salen) in cancer cells. DFO (25 mg/kg) reduced the onset of Fe(Salen) (25 mg/kg)-induced acute liver and renal dysfunction. DFO (300 mg/kg) improves survival rate after systematic injection of a fatal dose of Fe(Salen) (200 mg/kg) in mice. DFO enables the use of higher Fe(Salen) doses to treat progressive states of cancer, and it also appears to decrease the acute side effects of Fe(Salen). This makes DFO a potential antidote candidate for Fe(Salen)-based cancer treatments, and this novel strategy could be widely used in minimally-invasive clinical settings., (Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.)

We previously investigated the utility of μ-oxo N,N'- bis(salicylidene)ethylenediamine iron (Fe(Salen)) nanoparticles as a new anti-cancer agent for magnet-guided delivery with anti-cancer activity. Fe(Salen) nanoparticles should rapidly heat up in an alternating magnetic field (AMF), and we hypothesized that these single-drug nanoparticles would be effective for combined hyperthermia-chemotherapy. Conventional hyperthermic particles are usually made of iron oxide, and thus cannot exhibit anti-cancer activity in the absence of an AMF. We found that Fe(Salen) nanoparticles induced apoptosis in cultured cancer cells, and that AMF exposure enhanced the apoptotic effect. Therefore, we evaluated the combined three-fold strategy, i.e., chemotherapy with Fe(Salen) nanoparticles, magnetically guided delivery of the nanoparticles to the tumor, and AMF-induced heating of the nanoparticles to induce local hyperthermia, in a rabbit model of tongue cancer. Intravenous administration of Fe(Salen) nanoparticles per se inhibited tumor growth before the other two modalities were applied. This inhibition was enhanced when a magnet was used to accumulate Fe(Salen) nanoparticles at the tongue. When an AMF was further applied (magnet-guided chemotherapy plus hyperthermia), the tumor masses were dramatically reduced. These results indicate that our strategy of combined hyperthermia-chemotherapy using Fe(Salen) nanoparticles specifically delivered with magnetic guidance represents a powerful new approach for cancer treatment.

A photosystem II-enriched membrane (PSII-em) consists of the PSII core complex (PSII-cc) which is surrounded by peripheral antenna complexes. PSII-cc consists of two core antenna (CP43 and CP47) and the reaction center (RC) complex. Time-resolved fluorescence spectra of a PSII-em were measured at 77 K. The data were globally analyzed with a new compartment model, which has a minimum number of compartments and is consistent with the structure of PSII-cc. The reliability of the model was investigated by fitting the data of different experimental conditions. From the analysis, the energy-transfer time constants from the peripheral antenna to CP47 and CP43 were estimated to be 20 and 35 ps, respectively. With an exponential time constant of 320 ps, the excitation energy was estimated to accumulate in the reddest chlorophyll (Red Chl), giving a 692 nm fluorescence peak. The excited state on the Red Chl was confirmed to be quenched upon the addition of an oxidant, as reported previously. The calculations based on the Förster theory predicted that the excitation energy on Chl29 is quenched by ChlZD1(+), which is a redox active but not involved in the electron-transfer chain, located in the D1 subunit of RC, in the other monomer with an exponential time constant of 75 ps. This quenching pathway is consistent with our structure-based simulation of PSII-cc, which assigned Chl29 as the Red Chl. On the other hand, the alternative interpretation assigning Chl26 as the Red Chl was not excluded. The excited Chl26 was predicted to be quenched by another redox active ChlZD2(+) in the D2 subunit of RC in the same monomer unit with an exponential time constant of 88 ps.

Research on controlled drug delivery for cancer chemotherapy has focused mainly on ways to deliver existing anti-cancer drug compounds to specified targets, e.g., by conjugating them with magnetic particles or encapsulating them in micelles. Here, we show that an iron-salen, i.e., μ-oxo N,N'- bis(salicylidene)ethylenediamine iron (Fe(Salen)), but not other metal salen derivatives, intrinsically exhibits both magnetic character and anti-cancer activity. X-Ray crystallographic analysis and first principles calculations based on the measured structure support this. It promoted apoptosis of various cancer cell lines, likely, via production of reactive oxygen species. In mouse leg tumor and tail melanoma models, Fe(Salen) delivery with magnet caused a robust decrease in tumor size, and the accumulation of Fe(Salen) was visualized by magnetic resonance imaging. Fe(Salen) is an anti-cancer compound with magnetic property, which is suitable for drug delivery and imaging. We believe such magnetic anti-cancer drugs have the potential to greatly advance cancer chemotherapy for new theranostics and drug-delivery strategies.

Cellular reactive oxygen species (ROS) production is increased by both temperature and anticancer drugs. Antioxidants are known to suppress ROS production while cancer patients may take them as dietary supplement during chemotherapy and hyperthermic therapy. We examined changes in ROS production in prostate cancer cells in the presence of various anticancer drugs and antioxidants at different temperatures. ROS production was increased with temperature in cancer cells, but not in normal cells; this increase was potently inhibited by ascorbic acid. ROS production was also increased in the presence of some anticancer drugs, such as vinblastine, but not by others. Dietary antioxidant supplements, such as β-carotene, showed variable effects. Ascorbic acid potently inhibited ROS production, even in the presence of anticancer drugs, while β-carotene showed no inhibition. Accordingly, our results suggest that cancer patients should carefully choose antioxidants during their cancer chemotherapy and/or hyperthermic therapy.

Two-dimensional condensation was initiated in a self-assembled mixed monolayer of spiropyran and octadecanol by a nanosecond laser pulse. The dynamics of the process were monitored using nanosecond pump-probe Brewster angle microscopy. Domain growth followed a power law with a growth exponent of 0.47 at a velocity approaching 20 ms(-1). This represents a limit for the rate of longitudinal signaling of pressure waves through a self-assembled amphiphilic layer at an interface and adds to our understanding of signal transmission rates in biomimetic membranes where morphological change in one region can be signaled to a more remote region.

Loose interaction between the glycolytic enzymes glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and phosphoglycerate kinase (PGK) was visualized in living CHO-K1 cells by fluorescence resonance energy transfer (FRET), using time-domain fluorescence lifetime imaging microscopy. FRET between active tetrameric subunits of GAPDH linked to cerulean or citrine was observed, and this FRET signal was significantly attenuated by coexpression of PGK. Also, direct interaction between GAPDH-citrine and PGK-cerulean was observed by FRET. The strength of FRET signals between them was dependent on linkers that connect GAPDH to citrine and PGK to cerulean. A coimmunoprecipitation assay using hemagglutinin-tagged GAPDH and FLAG-tagged PGK coexpressed in CHO-K1 cells supported the FRET observation. Taken together, these results demonstrate that a complex of GAPDH and PGK is formed in the cytoplasm of living cells.

LBP-1 proteins form dimers and act as transcription factors that activate a number of genes related to cell growth and differentiation. LBP-1a and LBP-1c are localized in the cytoplasm when transiently expressed in cultured cells, but translocated into the nucleus after forming heterodimers with LBP-1b, which is a splicing variant of LBP-1a with an intrinsic nuclear localization signal (NLS). Here, we report that LBP-1b showed potent transactivation activity, and that forcibly expressed LBP-1a and LBP-1c in the nucleus essentially exhibited very little or no transactivation activity. Mutations in the NLS that abolished the NLS activity of LBP-1b also abrogated the transactivation activity. We have found that LBP-1 proteins contain a putative sterile alpha motif domain indispensable for their dimerization capability in the C-terminal region. To demonstrate whether homo- and heterodimers composed of LBP-1a and/or LBP-1c are generated in the nucleus, we applied the FLIM-based fluorescence resonance energy transfer imaging technique to living cells. It revealed that dimers composed of LBP-1a and LBP-1c were re-formed probably by a partner-exchange of LBP-1b-containing heterodimers.

The chirp effect on a X-ray emission intensity from a CsCl aqueous solution jet irradiated by femtosecond pulses was systematically studied. The p-polarized chirped pulses were more efficient as compared with the shortest pulses determined by the spectral bandwidth. The negatively-chirped pulses of approximately 240 fs duration produced up to 10 times larger X-ray intensity as compared with the transform-limited 160 fs pulses. The angular dependence of X-ray generation can be explained by the resonant absorption. Numerical simulations of electron density evolution due to the avalanche and multi-photon absorption supports qualitatively well the experimental observations.

The tumor suppressor von Hippel-Lindau (VHL) gene product forms a complex with elongin B and elongin C, and acts as a recognition subunit of a ubiquitin E3 ligase. Interactions between components in the complex were investigated in living cells by fluorescence resonance energy transfer (FRET)-fluorescence lifetime imaging microscopy (FLIM). Elongin B-cerulean or cerulean-elongin B was coexpressed with elongin C-citrine or citrine-elongin C in CHO-K1 cells. FRET signals were examined by measuring a change in the fluorescence lifetime of donors and by monitoring a corresponding fluorescence rise of acceptors. Clear FRET signals between elongin B and elongin C were observed in all combinations, except for the combination of elongin B-cerulean and citrine-elongin C. Although similar experiments to examine interaction between pVHL30 and elongin C linked to cerulean or citrine were performed, FRET signals were rarely observed among all the combinations. However, the signal was greatly increased by coexpression of elongin B. These results, together with results of coimmunoprecipitation experiment using pVHL, elongin C and elongin B, suggest that a conformational change of elongin C and/or pVHL was induced by binding of elongin B. The conformational change of elongin C was investigated by measuring changes in the intramolecular FRET signal of elongin C linked to cerulean and citrine at its N- and C-terminus, respectively. A strong FRET signal was observed in the absence of elongin B, and this signal was modestly increased by coexpression of elongin B, demonstrating that a conformation change of elongin C was induced by the binding of elongin B.

Refractive index measurement using an interferometric imaging system and observation of chemical wave shapes were carried out during chemical wave propagation of a cerium-catalyzed Belousov-Zhabotinsky (BZ) reaction. Densities increased as chemical waves propagated in samples without NaBr, and decreased in samples with NaBr. Concentration changes of malonic acid, bromomalonic acid, and BrO3- were estimated from Raman spectral measurements in a stirred batch BZ reaction, and these also exhibited differences between samples with and without NaBr. It is proposed that a reaction subset yielding low molecular weight carboxylic acids is predominant in samples with NaBr, whereas a pathway leading to dibromoacetic acid or tribromoacetic acid production is the major process in samples without NaBr.